This core resulted from the reorganization and restructuring of two of our previous cores, i.e. the Cell Biology and Molecular Biology Cores. The latter had evolved significantly over the years in response to the shifting needs of our investigators. However, in January 2007, Dr. Shouying Du, the Core's full-time Research Associate left to pursue her clinical training. This provided an opportunity to reassess how to best support the on-going and future needs of the Center members, by obtaining their input. As to the Cell Biology Core, while the instrumentation base and services of its Subcellular-Organelle and Equipment Subcore had kept expanding, the need for purified organelle and membrane preparations had declined substantially, due to shifting needs of our investigators. The combination of these two developments provided us with the opportunity to review and reassess the needs of our investigators for the resources and services offered through these two entities and to restructure them into a new and expanded core under the present title. The Center's external Advisory Board and the internal Executive Committee were presented with our needs and rationale for restructuring and approved the establishment of the present core starting with grant year 3 (i.e. 3/1/07). Thus, the core pooled the already extensive and critically needed/used instrumentation base and the menu of analytical services (multi-detection HPLC) of the Subcellular-Organelle and Equipment Subcore with that of the previous Molecular Biology Core into a new and expanded Central Core (see details below). Furthermore, to the analytical resources and services offered by the expanded base above, additional state-ofthe- art analytical and metabolic resources and services were added through two newly formed subcores, i.e.: a Mass Spectrometry-Based Proteomics Subcore (Proteomic Subcore) and a Small Molecule Identification/Mass Spectrometry Subcore (Small Molecule Subcore). The detailed descriptions of the Central Core and each of the two Subcores are presented in their respective sections below. In the process, support for the USC Institute of Genetic Medicine Microarray Facility, a Subcore of the prior Molecular Biology Core, was eliminated, along with the costs to the Center grant associated with these services. This was done in part due to the reduced interest for this service. However, microarray services will otherwise remain available to the Center Members who may need them. The following faculty were appointed to direct the new core and its subcores: Murad Ookhtens, Ph.D., Central Core Director (5% effort) Ebrahim Zandi, Ph.D., Mass Spectrometry-Based Proteomics Subcore Director (10% effort) Stan Louie, Pharm. D., Small Molecule Identification/Mass Spectrometry Subcore Director (5% effort) Besides directing the Central Core, Dr. Ookhtens will co-ordinate and work closely with the two subcore directors to insure that their services remain responsive to the Center's objectives and needs. Drs. Zandi and Louie will each direct their respective subcores and will communicate with Dr. Ookhtens regarding their usage and reporting activities. As in the past, the core and subcore directors will be required to report their respective performances during the Executive Committee meetings. In addition to the above. Dr. Andrew Stolz, Director of the previous Molecular Biology Core, will continue serving at no cost to the Center, as an advisor to investigators who need the use of some of the resources and instruments that were previously under the Molecular Biology Core. He will thus assist Dr. Ookhtens for the optimum utilization of these, as well as identify essential future equipment upgrades and acquisitions. The Central Core and the Mass Spectrometry-Based Proteomics Subcore are located in the Hoffman Medical Research (HMR) building, with the Small Molecule Identification/Mass Spectrometry Subcore located next door in the School of Pharmacy building.